I had two 10 year old boys at my house on Saturday. They were bored. Complained that they were bored. I ignored them. Told them I wasn't there to entertain them.
So - they played hide and seek. They raced around the neighborhood on their scooters, one of them teaching the other how to do stuff. They got into my child instruments. played the Kazoo. Did such a good job on the drums that I think they should join a drum line.
They did what kids used to do before electronics were invented.